| 摘要 |
PURPOSE:To test the entire area of a directory memory even with the small capacity of a main storage device, by changing bit positions of addresses stored in the directory memory. CONSTITUTION:In a buffer storage device 1, a request address (a) from a CPU2 is supplied to a comparator 14 and compared with an address (b) read out of a directory memory 12 through a resetting circuit 16. When the both are coincident, a coincidence signal (c) is supplied to a control part 11, which while reading data out of a memory 13, controls a multiplexer 17 to pass the data to the CPU2. When not, the control part 11 outputs a data request signal (d) to send an address (a) to a bus 100, and data (e) is read out of a main storage device 3 and sent to the CPU2. At the same time, current readout address information is written in the memory 12, and the data (e) is also written in the memory 13. Then, an interchanging circuit 15 and the resetting circuit 16 are controlled to changes the bit positions of the memory 12 and to perform resetting on an output side. |
